The present disclosure relates to responding devices and responding methods.
A responding device has been conventionally known which receives a request via a communication network and sends a response to the request received. Examples of the responding device include image forming apparatuses such as printers, multifunction printers, and multifunction peripherals (MFPs). For energy saving, an image forming apparatus being a responding device transitions to a power-saving operating mode (hereinafter, referred to as “standby mode”) once a predetermined period of time has passed while a user is not using the image forming apparatus. However, once in the standby mode, the image forming apparatus takes time to transition back to an operating mode in which the user can use the image forming apparatus (hereinafter, referred to as “normal mode”).
For example, when a host computer sends information request data (a request) for acquiring information about the image forming apparatus to the image forming apparatus in the standby mode via the communication network, the image forming apparatus transitions from the standby mode to the normal mode and sends response data (a response). It therefore takes some time before the response data is sent, slowing response. Furthermore, when the host computer sends information request data a number of times, the image forming apparatus transitions from the standby mode to the normal mode a number of times. As a result, the image forming apparatus can stay in the standby mode for a shorter period of time, and thus the energy-saving effect is reduced.
To deal with the problem, a technique is directed to allowing the response data to be sent while the apparatus is in the standby mode. For example, a certain image processing device includes two central processing units (CPUs) including a main CPU for responding during the normal mode and a sub-CPU for responding during the standby mode.
In such an image processing device, the main CPU first stores the response data sent in a random access memory (RAM) of the main CPU during the normal mode. Then, when the image processing device transitions to the standby mode, the sub-CPU retrieves frequently used response data out of the RAM of the main CPU and stores the data in a RAM of the sub-CPU.
Thus, frequently used data is stored in the RAM of the sub-CPU when the image processing device transitions from the normal mode to the standby mode. Consequently, the sub-CPU can create response data using the data stored in the RAM of the sub-CPU and send the data during the standby mode.